Motor-driven toothbrush



` June 7g 92?.

G. W. BAIRD ET AL MOTOR DRIVEN TGOTHBRUSH y Filed Aug. 18. 1924 IiiPatented June 7, 1927.

GLEN WILLIAM BAIRD AND ARTHUR LAMB, 0F DBUMMOND, IDAHO.

MOTOR-DRIVEN TOOTHBRUSH.

Application led August 18, 1924. Serial No. 732,799.

This invention relates to improvements in power driven tooth brushes. ln

The primary object of this inventlon 1s the provision of an electricallyoperated tooth brush embodying novel means for .reversibly driving abrush head. h

A further and important object of this mvention is the provision of anovel type of electrically operated tooth brush, embodying a brush headand means for reversibly driving the same in either direction at varyingspeeds.

A further object of this invention is the provisionV of an improvedtooth brush embodying a brush head which may be driven continuously inyeither `direction about 1ts axis. A further object of this inventionlis the provision of a power driven brush` including a novel changespeed device which may be used to perform the dual function of changingthe speed of rotation of a brush, or -of reversing the direction ofdrive thereof.

Other objects and advantages of this invention will be apparent duringthe course of the following detailed description.

In the accompanying drawing, forming a part of this specification, andwherein similar reference characters designate correspending partsthroughout the several views.

Figure 1 is a side elevation, partly in section, of the'improved powerdriven brush showing details thereof.

Fig. 2 is a fragmentary plan view of the improved tooth brush structure,showing the associated details thereof.

Fig. 3 is a fragmentary sectional view of a portion of the change speedand reversing mechanism.

Fig. 4 is a cross sectional view taken through a guard or shield memberprovided for a brush head and showing the latter in associated relation.j

In the drawing, wherein for the purpose of illustration is'shown only apreferred embodiment of the improved power driven tooth brush, theletter A may generally designate the improved power driven tooth brush,which may include a base B, upon which a motor C is mounted for theoperation of a, driven shaft D; the latter being connected as by speedchanging and reversing mechanism E tothe motor details. A

brush head F may be provided, of a novelf in frictional driving contactwit the outerv detachable ty e, which may be associated with means shaftD.

The base B is preferably flat, and preferably elongated, at one endhaving the motor supported thereon as by legs 15, either rigidly orintegrally connected with the base B, so that the vertically disposedvertical manner, preferably integral with' the base B, whichintermediate its ends is provided with an opening 26 within which abushing 27 fits forrotatably receiving the cylindrical shaped forwardend 29 of the driven shaft D.

The driven shaft D is of novel construction, including the end 29 abovelmentioned, while adjacently connected to the bearing end 29 is apositioning flange 30 adapted to abut the rear edge and surface of thebushmg 27, and standard 25. A polygonal shaped body portion 31 of thedriven shaft D extends rearwardly on a horizontal axis, and at itsextreme rear end isprovided with a reduced portion 33 which is journaledwithin a suitable bearing extension 35 provided on the motor housing.

rI his body portion 31 of the driven shaft D .is-preferably triangularin cross section, and slidably receives detailsv of the speed chandingand reversing mechanism E which wlll be subsequently described.

The base B between the standard 25 and the motor D preferably'has anopening' 38 therem within which an anti-friction bearing or bushingstructure 39 is mounted, to rotatably receive a stub shaft 40 of va,large driven gear 41, referably of the metal disc type, which is Xedwith the stub shaft 40 and disposed in a horizontal plane over the baseB, so that the outer periphe thereof is for connection with driven.

l periphery of the motor driven friction vided with a polygonal opening52 therein for slidably receiving the dportion 3 1 of the shaft Dtherethrough,an furthermore includes the ring shaped resilient wheelportionv 55, preferably of rubber .which is supported between flanges 56and 57 rigid: with the central portion 5l, and which resilient portion55 is in sliding engagement at its outer periphery upon the top surface58 of the large wheel 41.

Means is provided to shift the wheel 'structure k50 along the shaftortion 3l, which includes a rod 60 mounted) on a horizontal axis withina passageway 61 at the top of the standard 25, and which at its rear endis v downturned, at 62, and providing the biof course provided forholding furcated lower end 63 which is splined upon the portion 51 ofthe slidin wheel 50, .and by means of which the whee may be slid as therod is drawn throu h the opening 61 in the top of the standar 25.``Means is the wheel in a determined location, and is means includes aplurality of notches 65 formed at various spaced intervals' alon the topedge of the rod 60, and into whic the back end 66 of a resilient spring67 may snap to hold the rod ina predetermined position. Spring 67 is, ofcourse, resiliently mounted at its forward end by means of a set screw69 upon the top of the standard 25. The ro 60 extends forwardly of thestandard 25,

and has a finger engagin knob thereon.

From the foregoing escription it is a parensejust how the driven shaft Dmay opera When the wheel structure 50 is most forwardly positioned onthe shaft body 31, the wheel 50 will be in engagement with the topsurface of the motor dbriven wheel 41,.'at one side of the axis of saidmotor` driven wheel 41, and as the wheel50 is moved by the means Eforwardly' and towards the axis of the rotating wheel 41, it is readilyapparent that the s eed of the shaft D will decrease. As the wlieel 50moves across the axis of rotation of the-wheel 41l the drive of theshaft D will be negli 'ble, and after it has passed this axis in aorward 4direction the wheel 50 will be driven in a reverse rotation fordriving thel driven shaft D likewise in a reverse rotation. Thus, byplacing the wheel 50 at the desired side of axis of rotation of thewheel 41, the driven shaft D may be driven in the desired direction,`and the speed Aratio thereof may be varied `by moving the wheel 50 fromor away from the axis of rotation of the wheel 4l. Referring moreparticularly now to details of the brush and its connecting structure, aflexible housing is provided as part of the means G, which at its rearend is connected by means of a nut 81 -to the externally screw threadedstub extension 82 through which rthe forward end 29 of the driven shaftD extends. A driven'chain 85 extends longitudinally through thishousingl 80, which is of a iiexible nature, including a plurality of-relatively long links 86, which may be of wire or the like, and loopedas at 87, at their ends, for'universal jointed connection with similarloops provided'upon adjacent links-86. At its outermost or forward endthe flexible housing 80 has a cylindrical shaped hollow handle 89lixedly mounted thereon, within which a bearing or bushing 90. isswiveled, and which ia -provided with a longitudinally extendingpassageway 91\therethrough rotatably receiving a socket connecting piece92. At its rear end 92 is provided with a guide ange 95` to pre'- Vventforward longitudinal movement of the v socket piece 92 outwardly of thep handle 'bushing 90. At its extreme rear end the socket connectingpiece 92 is provided with ahook or analogous element 95a which isconnected with the foremost link 86 of the driven chain 85. Integralwith the bushing or handle piece is a shield portion' .98 which extendsforwardly of the fronted'ge 99 of the handle structure, and which is con-` cavo convex in cross section, as is illustrated in Figure 4 of thedrawings.

The brush head F includes a shank portion 101 adapted to have adetachable bayonet jointed connection, at 102, with the forwardlyprojecting end of the connecting socket piece 92. This brush head 101includes a ody 105 having outwardly extending tufts 106 provided inspaced rows about the same.

The operation of the brush structure will be apparent from the foregoingdescription, and the brush head Fgmay be electrically driven in eitherdirection about its axis, depending upon whether the teeth in the upperor lower jaws are to be brushed. Dentists are in accord with the correctmethod of brushing teeth, which should be a one way brushing, and fromthe gums toward the outer edges of the'teeth. With the t pe ofpowerdriven tooth brush herein descri ed this correct brushing of theteeth is rendered possible, and the vbrush head may be driven in theproper vdirection depending upon whether the inside or outside of theteeth are to bebrushed, or the teeth in the upper or lower jaws are tobe cleansed. The shield extending longitudinally at one side of thebrush head not only guards the'brush, but

prevents splattering of foreign matter. YThe la reversible drive for thebrush head prevents the tufts of brushes from Wearing in one inclineddirection, and are uniformly Worn and maintained in their outstandingrelation incident to the fact that the brush is alternately used as thedirection of rotation of the same is reversed.

Variouschanges in the shape size, and arrangement of parts may be madeto the form of invention herein shown and described, without departingfrom the spirit of the same or the scope of the claim.

We claim:

vIn a motor driven tooth brush thel combination of 'a horizontallysupported base, a'. motor mounted on the base having a drive shaftvertically disposed in right angled relation with the base, a driveWheel on the shaft between the motor and the base, a'relatively largeWheel having a spindle extending from one side thereof and being smootha'nd fiat on the opposite side thereof, means rotatably supporting saidspindle in the horizontal base with the relatively large Wheelhorizontally supported above the horizontal base with its smooth Hatside uppermost and at its periphery in driven engagement i With theperipheral edge of the motor Wheel, a 'standard rigid With the base inright angled vertically upstanding relation therethe upper surface ofthe relatively large Wheel, the ength of the driven shaft above therela'tivel large Wheel being such that the friction Wheel may be sliddiametrically across the relatively large Wheel into engagementtherewith at the opposite sides of the axis of rotation of therelatively large wheel, and operating means slidably carried by thestandard for moving the friction wheel and holding it in a desiredengagement with the relativelylarge wheel for drive of the drivenshaft.l

GLEN l/VILLIAM BAIRD.

ARTHUR LAMB.

